Re: Alternative approach to scrolling, with demos

This looks good Philip. Regions would still have to exist in markup though,
correct? In order to comply with 608/708, I forget which one.

Do you have an example of how the specification would change to implement
this new method?


On Sun, Mar 30, 2014 at 1:41 AM, Philip Jägenstedt <philipj@opera.com>wrote:

> Hi all,
>
> As promised, I have put together demos to illustrate how the
> alternative approach to scrolling [1,2] would work in practice. The
> way I have gone about this is to assume a baseline of WebVTT without
> regions, and to try to solve each problem in the simplest way I could
> find. The demos make use of basic TextTrack and WebVTT support. I've
> tested them in Opera, Safari and Chrome.
>
> == Scrolling as an overlap avoidance ==
>
> Demo: http://people.opera.com/philipj/2014/03/vttscroll/simple.html
>
> When a cue overlaps, it's moved down until it doesn't overlap, then
> all the cues are moved up. Scrolling is implemented by moving cues,
> not their container.
>
> This approach makes things much more similar to the regular overlap
> avoidance. You will end up with cues occupying approximately the same
> space in both modes, the only difference is the order.
>
> == Background box tweaking ==
>
> Demo: http://people.opera.com/philipj/2014/03/vttscroll/background.html
>
> WebVTT doesn't do a good job with the cue background right now. The
> only thing you can put a background on is the line box. One small
> improvement to this would be to allow a background on the cue box
> instead. This demo does exactly that, and visually it looks the same
> as a single region background.
>
> == Clipping to a maximum number of lines ==
>
> Demo: http://people.opera.com/philipj/2014/03/vttscroll/clip.html
>
> In the demo captions there can be 4 lines visible at the same time,
> but the top line is a bit distracting. This demo implements a possible
> solution for this problem, by clipping the group of cues to a maximum
> number of lines.
>
> == Absolute positioning and scrolling ==
>
> Demo: http://people.opera.com/philipj/2014/03/vttscroll/absolute.html
>
> Finally, an idea for how scrolling might work with absolutely
> positioned cues. You simply position all the cues at the point where
> scrolling should begin, and they'll scroll up from there.
>
> [1]
> http://lists.w3.org/Archives/Public/public-texttracks/2013Nov/0012.html
> [2]
> http://lists.w3.org/Archives/Public/public-texttracks/2014Jan/0025.html
>
> Philip
>
>